Aqueous dispersions of acrylate modified alkyd resins and use thereof

ABSTRACT

Aqueous dispersion of an acrylate-modified alkyd resin, preparable in the presence of at least one water-miscible diol by (1) dispersing in water at least one alkyd resin containing pendant and/or terminal allyloxy groups, (2) graft copolymerizing a mixture of methacrylic acid and at least one further, carboxyl-free olefinically unsaturated monomer in dispersion 1, and (3) once or n times graft copolymerising (3.1) at least one olefinically unsaturated monomer which is free from acid groups and/or (3.2) at least one mixture of at least one olefinically unsaturated monomer which contains acid groups and at least one olefinically unsaturated monomer which is free from acid groups, in dispersion 2 or 2 to n−1, with the proviso that in step (3) or (n) of the process, acid groups are incorporated in a total amount to not more than 90 mol % of the amount of acid groups incorporated in step (2) of the process.

This application is a National Phase Application of PCT/EP00/11616 filedon Nov. 22, 2000.

The present invention relates to novel dispersions of acrylate-modifiedalkyd resins. The present invention also relates to the use of the noveldispersions as novel air-drying or thermally curable coating materials,adhesives, and sealing compounds, and to the use for preparing them. Thepresent invention additionally relates to novel coatings, adhesivefilms, and seals on and in primed or unprimed substrates, produciblefrom the novel coating materials, adhesives, and sealing compounds. Thepresent invention relates not least to the novel primed and unprimedsubstrates which comprise the coatings, adhesives, and seals.

Alkyd resins and modified alkyd resins, owing to their advantageousperformance properties, constitute the binder base in about a third ofall coating materials worldwide (in this respect see all also RömppLexikon Lacke und Druckfarben, Georg Thieme Verlag, Stuttgart, New York,“alkyd resins”, pages 20 to 22). It is therefore very important onecological grounds to provide alkyd resins and especially modified alkydresins, which can be dispersed or are soluble in water without detrimentto their advantageous performance properties and which are hence able toform the basis for aqueous coating materials, adhesives, and sealingcompounds.

Alkyd resins generally offer the advantage that they require nocosolvents for forming a film. A disadvantage is that they need arelatively long period of time for drying. Dispersions of acrylatecopolymers, although drying more quickly, do need cosolvents foreffective film formation. Acrylate-modified alkyd resins combine the twoadvantages of the individual components without the need to toleratetheir disadvantages. It is therefore very important economically andtechnically to carry out further development of these alkyd resins inparticular in the sense outlined above.

International patent application WO 98/13404 discloses the preparationof an aqueous dispersion of an acrylate-modified alkyd resin for whichfirst of all a polyurethane-alkyd resin is prepared in methyl ethylketone. After the polyurethane-alkyd resin has been neutralized it isdispersed in water, after which the methyl ethyl ketone is removed,except for a residual fraction, by azeotropic distillation. Thereafter,at least one olefinically unsaturated monomer substantially having noreactive functional groups other than the double bond is (co)polymerizedin said dispersion. These aqueous dispersions give high-quality,low-yellowing, weathering-stable, scratch-resistant, and high-glosscoatings. Nevertheless, they have the disadvantage that they can beprepared only on the basis of the comparatively expensive polyurethanes.Moreover, the possibility of varying the profile of properties of thedispersions further by the incorporation of reactive functional groupsis lost. Not least, the azeotropic distillation of the relatively largeamounts of solvents presents safety and economic problems.

It is an object of the present invention to provide novel aqueousdispersions of acrylate-modified alkyd resins which no longer have thedisadvantages of the prior art but for whose preparation instead it isonly necessary to use such small amounts of solvents that it is nolonger necessary to remove them from the dispersions. Moreover, thenovel aqueous dispersions ought also to be able to be prepared on thebasis of polyurethane-free alkyd resins. In the preparation of the novelaqueous dispersions, furthermore, it ought to be possible to modify thealkyd resins with olefinically unsaturated monomers which do containreactive functional groups in addition to the olefinically unsaturateddouble bond. Over and above this, the novel aqueous dispersions ought togive coating materials, adhesives, and sealing compounds which can beemployed broadly and which give coatings, adhesive films, and seals thatare of particularly high quality and long service life.

Found accordingly has been the novel aqueous dispersion of anacrylate-modified alkyd resin which is preparable in the presence of atleast one water-miscible diol by

(1) dispersing in water at least one alkyd resin containing based on itstotal amount from 0.1 to 10% by weight of pendant and/or terminalallyloxy groups to give the dispersion 1,

(2) subjecting a mixture of methacrylic acid and at least one further,carboxyl-free olefinically unsaturated monomer to graft copolymerizationin the dispersion 1 to give the dispersion 2, and

(3) once or n times subjecting

(3.1) at least one olefinically unsaturated monomer which is free fromacid groups and/or

(3.2) at least one mixture of at least one olefinically unsaturatedmonomer which contains acid groups and at least one olefinicallyunsaturated monomer which is free from acid groups

to graft copolymerization in the dispersion 2 or 2 to n−1 resulting fromthe respective preceding step (2) or (2) to (n−1) of the process, withthe proviso that in step (3) of the process or its repetitions (3) to(n) acid groups are incorporated in an amount which corresponds in totalto not more than 90 mol % of the amount of acid groups incorporated instep (2) of the process.

The novel aqueous dispersion of an acrylate-modified alkyd resin isreferred to below as dispersion of the invention,

further subject matter of the invention will emerge from thedescription.

In the light of the prior art it was surprising and unforeseeable forthe skilled worker that the dispersions of the invention, even withparticle sizes of up to 1 μm, were stable and free from gel specks,despite being substantially free from organic solvents. It was furthersurprising that for their preparation it was possible to do largelywithout organic solvents requiring removal from the dispersionafterward. Another surprise was the extremely broad applicability of thedispersion of the invention, which goes well beyond the technologicalfields in which acrylate-modified alkyd resins and their dispersions arecommonly used.

The dispersion of the invention has a high solids content. Said contentis preferably from 10 to 80%, more preferably from 15 to 70%, withparticular preference from 20 to 65%, with very particular preferencefrom 30 to 60%, and in particular from 40 to 55% by weight, based on thetotal amount of the dispersion of the invention.

The essential constituent of the dispersion of the invention is theacrylate-modified alkyd resin. Its molecular weight may vary very widelyand is guided primarily by the respective intended use of the dispersionof the invention. Its number-average molecular weight is preferably from2 000 to 100 000, in particular from 2 000 to 50 000. It is alsopossible for the acid number and the hydroxyl number to vary widely. Theacid number is preferably from 20 to 70, in particular from 30 to 40, mgKOH/g and the hydroxyl number is preferably from 10 to 150, inparticular from 30 to 90, mg KOH/g. The glass transition temperature maylikewise vary very widely. In accordance with the invention, however, itis of advantage if it lies above 0° C. It is preferably from 1 to 80°C., in particular from 2 to 60° C.

The preparation of the acrylate-modified alkyd resin for inventive usestarts from an alkyd resin which preferably has a number-averagemolecular weight of from 1 000 to 3 000 and in particular from 1 000 to2 000. The acid number is preferably from 15 to 40, in particular from30 to 35, mg KOH/g. The hydroxyl number is preferably from 30 to 150, inparticular from 40 to 60, mg KOH/g. The iodine number according to DIN53241-1 is from 0 to 200 g, in particular from 50 to 200 g, ofiodine/100 g. The glass transition temperature of the alkyd resin ispreferably below 0° C., in particular from −70 to −10° C. The oilcontent of the alkyd resins may likewise vary very widely and is guidedin particular by the requirements of the respective intended use. It ispreferred to employ a fatty acid content or an oil content of from 20 to80% by weight and in particular from 30 to 70% by weight (calculated astriglyceride; oil length), based in each case on the alkyd resin.

In accordance with the invention, the pendant and/or terminal allyloxygroup are present in the alkyd resin in an amount, based in each case onthe alkyd resin, of from 0.1 to 10%, preferably from 0.2 to 9%, morepreferably from 0.3 to 8%, with particular preference from 0.4 to 7%,with very particular preference from 0.5 to 6%, and in particular from0.6 to 5% by weight. The oxygen atom of the allyloxy group may be partof a urethane group, an ester group or an ether group which connects theallyl radical to the main chain of the alkyd resin. The oxygen atom ispreferably part of an ether group; in other words, allyl ether groupsare used with preference in accordance with the invention.

There are no special features to the method of preparing the alkydresins, which instead are prepared in accordance with the customary andknown methods of preparing alkyd resins from saturated and unsaturated,linear and branched, short-chain and long-chain alkylmonocarboxylicacids (oils, fatty acids), aromatic, optionally alkyl-substitutedmonocarboxylic acids, aliphatic and aromatic dicarboxylic acids,and—where they exist—their anhydrides, hydroxycarboxylic acids, diolsand higher polyfunctional polyols, and compounds which introduceallyloxy groups. It is also possible to use higher polyfunctionalaromatic carboxylic acids such as pyromellitic acid, hemimellitic acidand/or mellitic acid and/or their anhydrides, adducts of customary andknown polyisocyanates with compounds containing isocyanate-reactivefunctional groups such as hydroxyl groups and/or amino groups, abieticacid, rosin, epoxides, and/or epoxidized fatty acids as additionalstarting products.

The stirred tanks commonly used for condensation reactions are suitablefor the synthesis.

Examples of suitable alkylmonocarboxylic acids are present, for example,in natural oils such as linseed oil, soybean oil, tall oil, saffloweroil, cotton seed oil, castor oil, sunflower oil, groundnut oil, wood oilor ricinene oil. The fatty acids obtained from these are linseed oil,soybean oil, tall oil, safflower oil, cotton seed oil, castor oil,sunflower oil, groundnut oil, wood oil or ricinene oil fatty acid. Alsosuitable are isononanoic acid, 2-ethylhexanoic acid, coconut fatty acid,stearic acid and/or Juvandole fatty acid.

Examples of suitable aromatic monocarboxylic acids are benzoic acid orp-tert-butylbenzoic acid.

Examples of suitable dicarboxylic acids are phthalic acid, isophthalicacid, terephthalic acid, phthalic, isophthalic or terephthalicmonosulfonate, halophthalic acids such as tetrachloro- ortetrabromophthalic acid, oxalic acid, malonic acid, succinic acid,glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid,sebacic acid, undecanedicarboxylic acid, dodecanedicarboxylic acid,maleic acid, fumaric acid, itaconic acid, 1,2-cyclobutanedicarboxylicacid, 1,3 cyclobutanedicarboxylic acid, 1,2-cyclopentane-dicarboxylicacid, 1,3-cyclopentanedicarboxylic acid, hexahydrophthalic acid,1,3-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid,4-methylhexa-hydrophthalic acid, tricyclodecanedicarboxylic acid,tetrahydrophthalic acid or 4-methyltetrahydrophthalic acid. Thecycloaliphatic dicarboxylic acids can be used both in their cis form andin their trans form and also as a mixture of both forms.

Examples of suitable hydroxycarboxylic acids are 2-, 3-,4-hydroxybenzoic acid, ricinoleic acid, dihydroxypropionic acid,dihydroxysuccinic acid, dihydroxybenzoic acid, 2,2-dimethylolaceticacid, 2,2 -dimethylolpropionic acid, 2,2-dimethylolbutyric acid, and2,2-dimenthylolpentanoic acid.

Examples of suitable diols are ethylene glycol, 1,2- or 1,3-propanediol,1,2-, 1,3- or 1,4-butanediol, 1,2-, 1,3-, 1,4- or 1,5-pentanediol, 1,2-,1,3-, 1,4-, 1,5- or 1,6-hexanediol, pentyl hydroxypivalate, neopentylglycol, diethylene glycol, 1,2-, 1,3- or 1,4-cyclohexanediol, 1,2-, 1,3-or 1,4-cyclohexanedimethanol, trimethylpentanediol,ethylbutylpropanediol, the positionally isomeric diethyloctanediols,2-butyl-2 -ethylpropane-1,3-diol, 2-butyl-2-methylpropane-1,3 -diol,2-phenyl-2-methylpropane-1,3-diol, 2-propyl-2 -ethylpropane-1,3-diol,2-di-tert-butylpropane-1,3-diol, 2-butyl-2-propylpropane-1,3-diol,1-dihydroxymethylbicyclo[2.2.1]heptane, 2,2-diethylpropane-1,3-diol,2,2-dipropylpropane-1,3-diol, 2-cyclohexyl-2-methylpropane-1,3-diol,2,5-dimethylhexane-2,5-diol, 2,5 diethylhexane-2,5-diol,2-ethyl-5-methylhexane-2,5 -diol, 2,4-dimethylpentane-2,4-diol,2,3-dimethylbutane-2,3-diol, 1,4-(2′-hydroxypropyl)benzene or1,3-(2′-hydroxypropyl)benzene. In addition to or instead of these diolsit is also possible to use diols of higher molecular mass such aspolyester diols or polyether diols. It is preferred to employ the lowmolecular mass diols.

Examples of suitable polyols are triols such as trimethylolethane,trimethylolpropane or glycerol, especially trimethylolpropane, tetrolssuch as pentaerythritol or homopentaerythritol or sugar alcohols such asthreitol or erythritol, or pentitols such as arabitol, adonitol orxylitol or hexitols such as sorbitol, mannitol or dulcitol.

Examples of suitable compounds for introducing pendant and/or terminalallyloxy groups are allyl alcohol, 2 -hydroxyethyl allyl ether,3-hydroxypropyl allyl ether, trimethylolpropane monoallyl or diallylether, glycerol monoallyl or diallyl ether, pentaerythritol monoallyl,diallyl or triallyl ether, mannitol monoallyl, diallyl, triallyl ortetraallyl ether, allyl esters of dihydroxypropionic, dihydroxysuccinic,dihydroxybenzoic, 2,2-dimethylolacetic, 2,2-dimethylolpropionic,2,2-dimethylolbutyric or 2,2-dimethylolpentanoic acid, or allylurethane, of which trimethylolpropane monoallyl ether is of advantageand is therefore used preferably in accordance with the invention.

The above-described starting products and their amounts are selected soas to give alkyd resins with the profile of properties described above.The skilled worker is therefore able to determine the suitable startingproducts and proportions in each case with ease on the basis of his orher general knowledge in the art, where appropriate with the assistanceof simple preliminary rangefinding tests.

Prior to their further reaction, the alkyd resins containing allyloxygroups are diluted with at least one water-soluble or -dispersible diol,preferably ethylene glycol, propylene glycol and/or butylene glycol,particularly propylene glycol. It is preferred to employ only amountssuch that the resulting mixture is liquid. Preference is given to usingfrom 2 to 20%, in particular from 5 to 15% by weight of diol, based onthe mixture.

In accordance with the invention, the alkyd resins containing allyloxygroups are dispersed in an aqueous medium to give the dispersion 1.

The aqueous medium contains substantially water. It preferably furtherincludes at least one neutralizing agent, with which the acid groupspresent in the alkyd resin are partly or completely neutralized.Examples of suitable neutralizing agents for the potentially anionicgroups of the alkyd resin are alkali metal and alkaline earth metalhydroxides, oxides, carbonates or hydrogen carbonates, and also ammoniaand amines, such as trimethylamine, triethylamine, tributylamine,dimethylaniline, diethylaniline, triphenylamine, dimethylethanolamine,diethylethanolamine, methyldiethanolamine, 2-aminomethylpropanol,dimethylisopropylamine, dimethylisopropanolamine or triethanolamine.

The aqueous medium may further comprise minor amounts of organicsolvents and/or other dissolved solid, liquid or gaseous organic and/orinorganic substances of low and/or high molecular mass. In the contextof the present invention, the term “minor amount” means an amount whichdoes not rob the aqueous medium of its aqueous nature. Examples ofsuitable organic solvents are the above-described water-miscible diols,which can be supplied to the dispersion 1 directly and/or by way of themonomer feeds and/or initiator feeds of the graft copolymerizationstages (2) to (n) that are described below.

It is possible not least for the aqueous medium to include at least oneof the customary coatings additives described below. Suitable additivesare all those which do not partly or fully inhibit the multistage graftcopolymerization of the olefinically unsaturated monomers.

Alternatively, the aqueous medium may comprise straight water.

In accordance with the invention, in a stage (2), methacrylic acid andat least one further olefinically unsaturated monomer are subjected tograft copolymerization in the dispersion 1. Besides the olefinicallyunsaturated double bonds, the further olefinically unsaturated monomersmay contain other reactive functional groups—with the exception ofcarboxyl groups, examples being isocyanate-reactive, carbamate-reactive,N-methylol- or N-methylol ether-reactive or alkoxycarbonylamino-reactivegroups. What is important here is that, under the given reactionconditions and the subsequent storage of the dispersions of theinvention, these reactive functional groups do not undergo any reactionswith the carboxyl groups of the methacrylic acid or with other reactivefunctional groups that may be present. One example of reactivefunctional groups which meet these requirements is the hydroxyl group.

Examples of suitable further monomers (a) which can be used forpreparing the acrylate-modified alkyd resins of the invention and thedispersions of the invention are:

Monomers (a1):

Hydroxyalkyl esters of acrylic acid, of methacrylic acid or of anotheralpha,beta-olefinically unsaturated carboxylic acid which derive from analkylene glycol which is esterified with the acid or are obtainable byreacting the acid with an alkylene oxide, especially hydroxyalkyl estersof acrylic acid, methacrylic acid, crotonic acid or ethacrylic acid inwhich the hydroxyalkyl group contains up to 20 carbon atoms, such as2-hydroxyethyl, 2-hydroxypropyl, 3-hydroxypropyl, 3 -hydroxybutyl,4-hydroxybutyl acrylate, methacrylate, ethacrylate or crotonate;1,4-bis(hydroxymethyl)cyclohexane,octahydro-4,7-methano-1H-indenedimethanol or methylpropanediolmonoacrylate, monomethacrylate, monoethacrylate or monocrotonate; orreaction products of cyclic esters, such as epsilon-caprolactone, forexample, and these hydroxyalkyl esters; or olefinically unsaturatedalcohols such as allyl alcohol or polyols such as trimethylolpropanemonoallyl or diallyl ether or pentaerythritol monoallyl, diallyl, ortriallyl ether. These higher polyfunctional monomers (a1) are generallyused only in minor amounts. In the context of the present invention,minor amounts of higher polyfunctional monomers here are amounts whichdo not lead to crosslinking or gelling of the polyacrylate resins unlessthe graft copolymers of the invention are intended to be in the form ofcrosslinked microgel particles. Accordingly, the fraction oftrimethylolpropane diallyl ether can be from 2 to 10% by weight, basedon the total weight of the monomers (a1) to (a6) used to prepare thepolyacrylate resin.

Monomers (a2):

(Meth)acrylic, crotonic or ethacrylic alkyl or cycloalkyl esters havingup to 20 carbon atoms in the lkyl radical, especially methyl, ethyl,propyl, n-butyl, sec-butyl, tert-butyl, hexyl, ethylhexyl, stearyl andlauryl acrylate, methacrylate, crotonate or ethacrylate; cycloaliphatic(meth)acrylic, crotonic or ethacrylic esters, especially cyclohexyl,isobornyl, dicyclopentadienyl, octahydro-4,7-methano-1H-indenemethanolor tert-butylcyclohexyl (meth)acrylate, crotonate or ethacrylate;(meth)acrylic, crotonic or ethacrylic oxaalkyl or oxacycloalkyl esterssuch as ethyl triglycol (meth)acrylate and methoxyoligoglycol(meth)acrylate having a molecular weight Mn of preferably 550; or otherethoxylated and/or propoxylated, hydroxyl-free (meth)acrylic, crotonicor ethacrylic acid derivatives. These may include in minor amountshigher polyfunctional (meth)acrylic, crotonic or ethacrylic alkyl orcycloalkyl esters such as ethylene glycol, propylene glycol, diethyleneglycol, dipropylene glycol, butylene glycol, pentane-1,5-diol,hexane-1,6-diol, octahydro-4,7-methano-1H-indenedimethanol orcyclohexane-1,2-, -1,3- or -1,4-diol di(meth)acrylate;trimethylolpropane di- or tri(meth)acrylate; or pentaerythritol di-,tri- or tetra(meth)acrylate, and also the analogous ethacrylates orcrotonates. In the context of the present invention, minor amounts ofhigher polyfunctional monomers (a2) here are amounts which do not leadto crosslinking or gelling of the polyacrylate resins, unless theacrylate-modified alkyd resins of the invention are intended to be inthe form of crosslinked microgel particles.

Monomers (a3):

Olefinically unsaturated monomer carrying per molecule at least one acidgroup, with the exception of a carboxyl group, or a mixture of suchmonomers; examples are olefinically unsaturated sulfonic or phosphonicacids and/or their partial esters, such as ethene-, propene- orbutene-sulfonic or -phosphonic acid or alkyl or aryl monoesters ofphosphonic acids such as methyl, ethyl or phenyl ethene-, propene- orbutenephosphonate. In these monomers the olefinic double bonds arepreferably terminal.

Monomers (a4):

Vinyl esters of alpha-branched monocarboxylic acids having from 5 to 18carbon atoms in the molecule. The branched monocarboxylic acids may beobtained by reacting formic acid or carbon monoxide and water witholefins in the presence of a liquid, strongly acidic catalyst; theolefins may be cracking products of paraffinic hydrocarbons, such asmineral oil fractions, and may comprise both branched and straight-chainacyclic and/or cycloaliphatic olefins. The reaction of such olefins withformic acid or with carbon monoxide and water forms a mixture ofcarboxylic acids in which the carboxyl groups are seated predominantlyon a quaternary carbon atom. Other olefinic starting materials are, forexample, propylene trimer, propylene tetramer, and diisobutylene.Alternatively, the vinyl esters may be prepared conventionally from theacids, by reacting the acid with acetylene, for example. Particularpreference—owing to their ready availability—is given to using vinylesters of saturated aliphatic monocarboxylic acids having from 9 to 11carbon atoms that are branched on the alpha carbon atom.

Monomers (a5):

Reaction product of acrylic acid and/or methacrylic acid with theglycidyl ester of an alpha-branched monocarboxylic acid having from 5 to18 carbon atoms per molecule. The reaction of the acrylic or methacrylicacid with the glycidyl ester of a carboxylic acid having a tertary alphacarbon atom may take place before, during or after the polymerizationreaction. As component (a5) it is preferred to use the reaction productof acrylic and/or methacrylic acid with the glycidyl ester of Versatic®acid. This glycidyl ester is available commercially under the nameCardura® E10. For further details refer to Römpp Lexikon Lacke undDruckfarben, Georg Thieme Verlag, Stuttgart, New York, 1998, pages 605and 606.

Monomers (a6):

Olefinically unsaturated monomers which are substantially free from acidgroups, such as

olefins such as ethylene, propylene, but-1-ene, pent-1-ene, hex-1-ene,cyclohexene, cyclopentene, norbornene, butadiene, isoprene,cyclopentadiene and/or dicyclopentadiene;

methylolated (meth)acrylamides such as N-methylol-, N,N-dimethylol-,N-methoxymethyl-, N,N-di(methoxymethyl)-, N-ethoxymethyl- and/orN,N-di(ethoxyethyl)-(meth)acrylamide, which are used in particular whenthe acrylate-modified alkyd resins of the invention are intended to haveself-crosslinking properties (in this regard see Römpp Lexikon Lacke undDruckfarben, Georg Thieme Verlag, Stuttgart, New York, 1998, “curing”,pages 274 to 276);

vinylaromatic hydrocarbons, such as styrene, alpha-alkylstyrenes,especially alpha-methylstyrene, arylstyrenes, especiallydiphenylethylene, and/or vinyltoluene;

nitriles such as acrylonitrile and/or methacrylonitrile;

vinyl compounds such as vinyl chloride, vinyl fluoride, vinylidenedichloride, vinylidene difluoride; N-vinylpyrrolidone; vinyl ethers suchas ethyl vinyl ether, n-propyl vinyl ether, isopropyl vinyl ether,n-butyl vinyl ether, isobutyl vinyl ether and/or vinyl cyclohexyl ether;vinyl esters such as vinyl acetate, vinyl propionate, vinyl butyrate,vinyl pivalate, vinyl esters of Versatic® acids, which are sold underthe brand name VeoVa® by Deutsche Shell Chemie (for further detailsrefer to Römpp Lexikon Lacke und Druckfarben, Georg Thieme Verlag,Stuttgart, New York, 1998, page 598 and also pages 605 and 606) and/orthe vinyl ester of 2-methyl-2-ethylheptanoic acid; and/or

polysiloxane macromonomers having a number-average molecular weight Mnof from 1 000 to 40 000, preferably from 2 000 to 20 000, withparticular preference from 2 500 to 10 000, and in particular from 3 000to 7 000 and containing on average per molecule from 0.5 to 2.5,preferably from 0.5 to 1.5, olefinically unsaturated double bonds, suchas are described in DE-A-38 07 571 on pages 5 to 7, in DE-A-37 06 095 incolumns 3 to 7, in EP-B-0 358 153 on pages 3 to 6, in U.S. Pat. No.4,754,014 in columns 5 to 9, in DE-A-44 21 823 or in internationalpatent application WO 92/22615 on page 12 line 18 to page 18 line 10, oracryloyloxy silane-containing vinyl monomers, preparable by reactinghydroxy-functional silanes with epichlorohydrin and subsequentlyreacting the reaction product with methacrylic acid and/or hydroxyalkylesters of (meth)acrylic acid.

From these further suitable monomers (a) described by way of exampleabove, the skilled worker is able to select with ease the monomers (a)which are especially suitable for the respective intended use, on thebasis of their known physicochemical properties and reactivities. Ifdesired, the skilled worker may for this purpose carry out a fewpreliminary rangefinding tests. In particular, he or she will ensurewhen making this selection that the monomers (a) contain no reactivefunctional groups, particularly (potentially) ionic functional groups,which undergo unwanted interactions with the carboxyl groups of themonomeric or copolymerized methacrylic acid.

Where the acrylate-modified alkyd resins of the invention are intendedto be present in the form of crosslinked microgel particles, higherpolyfunctional monomers (a), especially the above-described higherpolyfunctional monomers (a1) and/or (a2), are employed in amounts whichlead to targeted crosslinking of the grafted-on (co)polymers.

In accordance with the invention, particular advantages result if themonomers (a) are selected such that the profile of properties of thegrafted-on (co)polymers is determined essentially by the (meth)acrylatemonomers (a) described above, with the other monomers (a),advantageously, broadly varying this profile of properties.

Very particular advantages result in accordance with the invention fromusing mixtures of the monomers (a1), (a2), and (a6), and also, whereappropriate (a3).

Viewed in terms of method, the preparation of the acrylate-modifiedalkyd resins of the invention has no special features but instead takesplace in accordance with the customary and known method of free-radicalemulsion polymerization in the presence of at least one polymerizationinitiator, as is described, for example, in patents DE-C-197 22 862,DE-A-196 45 761, EP-A-0 522 419 or EP-A-0 522 420.

In this context the monomers (a) and the methacrylic acid may also bebrought into the form of a preemulsion using part of a dispersion 1 andwater, said preemulsion then being metered slowly into an initial chargein which the actual emulsion polymerization takes place.

Examples of suitable polymerization initiators are oil-solubleinitiators which form free radicals, such as dialkyl peroxides, such asdi-tert-butyl peroxide or dicumyl peroxide; hydroperoxides, such ascumene hydroperoxide or tert-butyl hydroperoxide; peresters, such astert-butyl perbenzoate, tert-butyl perpivalate, tert-butylper-3,5,5-trimethylhexanoate or tert-butyl peroxy-2-ethylhexanoate;azodinitriles such as azobisisobutyronitrile; or C-C-cleaving initiatorssuch as benzpinacol silyl ethers. The initiators are used preferably inan amount of from 0.1 to 25% by weight, with particular preference from0.75 to 10% by weight, based on the total weight of the monomers (a).

In the aqueous emulsions, methacrylic acid and the monomers (a) are thenpolymerized with the aid of the abovementioned radical-forminginitiators at temperatures from 0 to 95° C. and preferably 40 to 95° C.When operating under superatmospheric pressure, the polymerization mayalso be conducted at temperatures above 100° C.

In the polymerization, the infeed of initiator may be commenced at acertain time, generally from about 1 to 15 minutes, before the feed ofthe monomers. Preference is further given to a process wherein theaddition of initiator is commenced at the same point in time as theaddition of the monomers and is ended some time later—for example, abouthalf an hour—after the addition of the monomers has been ended. Theinitiator is preferably added in a constant amount per unit time. Afterthe end of the addition of initiator, the reaction mixture is held atpolymerization temperature until (generally from 1.5 to 10 hours) all ofthe monomers used have undergone substantially complete reaction.“Substantially complete reaction” is intended to denote that preferably100% by weight of the monomers used have been converted but that it isalso possible for a small residual monomer content of not more than upto about 0.5% by weight, based on the weight of the reaction mixture, toremain unreacted.

Suitable reactors for the graft copolymerization include the customaryand known stirred tanks, stirred tank cascades, tube reactors, loopreactors or Taylor reactors, such as are described, for example, inpatents DE-B-1 071 241 or EP-A-0 498 583 or in the article by K. Kataokain Chemical Engineering Science, Volume 50, No. 9, 1995, pages 1409 to1416.

In accordance with the invention, it is of particular advantage to addat least one of the above-described water-soluble diols, especiallypropylene glycol, to the monomer feed and to the initiator feed.

This gives, after step (2) of the process, the dispersion 2.

In process step (3), in accordance with the invention, at least one ofthe above-described monomers (a) that are free from acid groups is(co)polymerized in dispersion 2, using the methods and apparatusdescribed above.

In another variant of the process of the invention, in step (3) of theprocess at least one mixture of

at least one olefinically unsaturated monomer (a3) containing acidgroups and/or at least one olefinically unsaturated monomer (a7)containing carboxyl groups, such as acrylic acid, methacrylic acid,ethacrylic acid, crotonic acid, maleic acid, fumaric acid, itaconicacid, mono(meth)acryloyloxyethyl maleate, mono(meth)acryloyloxyethylsuccinate and/or mono(meth)acryloyloxyethyl phthalate; and

at least one olefinically unsaturated monomer that is free from acidgroups, in particular at least one of the above-described monomers (a)that are free from acid groups,

is copolymerized or graft copolymerized in the dispersion 2. Here again,the above-described methods and apparatus are employed.

In accordance with the invention, in this variant of the process of theinvention, acid groups must only be incorporated in an amount whichcorresponds in total to not more than 90 mol %, preferably not more than80 mol %, more preferably not more than 60 mol %, with particularpreference not more than 50 mol %, with very particular preference notmore than 40 mol %, and in particular not more than 30 mol % of theamount of acid groups incorporated in the preceding process step (2).

In accordance with the invention, process step (3) results in thedispersion of the invention.

It is the particular advantage of the process of the invention and ofthe dispersion of the invention that its profile of properties may bevaried advantageously by repeating step (3) of the process.

Step (3) of the process may be repeated once here, giving fromdispersion 3 in process step (4) a further dispersion of the invention.However, process step (3) may be repeated a number of times, i.e., ntimes, giving from dispersions 2 to n−1 always dispersions 3 to n of theinvention, which are, however, modified in their respective profile ofproperties as compared with the dispersion produced in the respectivepreceding process step. In general it is sufficient here to repeat step(3) of the process twice. In special cases it may also be repeated threetimes or more.

Another particular variant is the result of repeating process step (3)using a mixture of at least one olefinically unsaturated monomercontaining acid groups and at least one olefinically unsaturated monomerthat is free from acid groups after having used at least one monomerthat is free from acid groups in the preceding process step (3). Thesame is also true conversely; that is, if in repeating process step (3)at least one monomer that is free from acid groups is used with themixture having been employed in the preceding process step (3).

For the repetitions of process step (3), too, the above-describedapparatus and methods are employed. As regards the upper limits on acidgroups which can be incorporated by process step (3) and itsrepetitions, the comments made above apply.

In the acrylate-modified alkyd resins of the invention, the proportionof graft-copolymerized polyacrylate to alkyd resin may vary very widely.The fraction, based on the acrylate-modified alkyd resin of theinvention, is preferably from 20 to 80%, more preferably from 30 to 70%,with particular preference from 40 to 60%, and in particular from 45 to55% by weight.

The acrylate-modified alkyd resins of the invention can be isolated fromthe dispersions of the invention in which they are obtained and can bepassed on for any of a very wide variety of end uses, especially insolventborne, water- and solvent-free pulverulent solid or water- andsolvent-free liquid coating materials, adhesives, and sealing compounds.

In accordance with the invention, however, it is of advantage to use thedispersions of the invention as they are for preparing aqueous coatingmaterials, adhesives, and sealing compounds or as aqueous coatingmaterials, adhesives, and sealing compounds which are air-drying,thermally curable or curable both thermally and with actinic radiation.In their use as coating materials they exhibit outstanding film formingproperties.

Besides the acrylate-modified alkyd resins of the invention, the aqueousadhesives of the invention may comprise further suitable customary andknown constituents in effective amounts. Examples of suitableconstituents are the customary coatings additives described below,insofar as they are suitable for the preparation of adhesives.

Besides the acrylate-modified alkyd resins of the invention, the aqueoussealing compounds of the invention may also comprise further suitablecustomary and known constituents in effective amounts. Examples ofsuitable constituents are likewise the customary coatings additivesdescribed below, insofar as they are suitable for the preparation ofsealing compounds.

The dispersions of the invention are suitable in particular forpreparing aqueous coating materials, especially aqueous paints. Examplesof aqueous paints of the invention are decorating paints, especially“do-it-yourself” decorating paints, surfacers, solid-cover topcoatmaterials, aqueous basecoat materials, and clearcoat materials.

In the aqueous paints, the acrylate-modified alkyd resins of theinvention are present advantageously in an amount of from 1.0 to 90%,preferably from 2.0 to 80%, with particular preference from 3.0 to 70%,with very particular preference from 4.0 to 60%, and in particular from5.0 to 55% by weight, based in each case on the total weight of therespective aqueous paint.

Furthermore, the aqueous paints may comprise at least one customarycoatings additive.

Customary coatings additives which are significant to performanceinclude color and/or effect pigments. The pigments may be composed oforganic or inorganic compounds. Owing to this large number of suitablepigments, therefore, the aqueous paints of the invention ensure auniversal breadth of use and make it possible to realize a large numberof color shades and optical effects. Examples of suitable pigments aredisclosed in Römpp Lexikon Lacke und Druckfarben, Georg Thieme Verlag,1998, pages 176, “Effect pigments”; pages 380 and 381 “Metal oxide-micapigments” to “Metal pigments”; pages 180 and 181, “Iron blue pigments”to “Black iron oxide”; pages 451 to 453, “Pigments” to “Pigment volumeconcentration”; page 563, “Thioindigo pigments”; and page 567, “Titaniumdioxide pigments”.

Further performance-significant, customary coatings additives arecrosslinking agents Examples of suitable crosslinking agents are aminoresins. Examples of suitable amino resins are customary and known, andnumerous products are available commercially.

Examples of highly suitable amino resins are melamine resins, guanamineresins or urea resins. In this context it is possible to use any aminoresin which is suitable for transparent topcoat materials or clearcoatmaterials, or a mixture of such amino resins. For further details referto Römpp Lexikon Lacke und Druckfarben, Georg Thieme Verlag, 1998, page29, “Amino resins”, and the text book “Lackadditive” [Additives forCoatings] by Johan Bieleman, Wiley-VCH, Weinheim, New York, 1998, pages242 ff., or to the book “Paints, Coatings and Solvents”, secondcompletely revised edition, Edited by D. Stoye and W. Freitag,Wiley-VCH, Weinheim, New York, 1998, pages 80 ff. Also suitable,furthermore, are the customary and known amino resins some of whosemethylol and/or methoxymethyl groups have been defunctionalized by meansof carbamate or allophanate groups. Crosslinking agents of this kind aredescribed in patents U.S. Pat. No. 4 710 542 and EP-B-0 245 700 and alsoin the article by B. Singh and coworkers “Carbamylmethylated Melamines,Novel Crosslinkers for the Coatings Industry” in Advanced OrganicCoatings Science and Technology Series, 1991, Volume 13, pages 193 to207.

Besides these crosslinking agents or instead of them it is also possiblefor further crosslinking agents to be present. Examples of suitablefurther crosslinking agents are compounds or resins containing siloxanegroups, compounds or resins containing anhydride groups, compounds orresins containing epoxide groups, blocked and/or nonblockedpolyisocyanates and tris(alkoxycarbonylamino)triazines such as aredescribed in patents U.S. Pat. No. 4 939 213, U.S. Pat. No. 5 084 541,U.S. Pat. No. 5 288 865 or EP-A-0 604 922.

Depending on the reactivity of the further crosslinking agent, it may beadded directly to the coating materials, adhesives, and sealingcompounds of the invention to give what is called a one-componentsystem. If, on the other hand, it is a particularly reactivecrosslinking agent, such as a polyisocyanate or an epoxide, this isgenerally not added until shortly before use to the coating materials,adhesives, and sealing compounds of the invention. The result in thiscase is what is known as a two-component or multicomponent system.

The use of crosslinking agents is omitted if the aqueous paints of theinvention are air-drying, i.e. oxidatively drying, or physically drying(cf. in this respect Römpp Lexikon Lacke und Druckfarben, Georg ThiemeVerlag, Stuttgart, New York, 1998, “Curing”, pages 274 and 275). Thesame applies accordingly to the aqueous coating materials and sealingcompounds.

The use of crosslinking agents is likewise omitted if theacrylate-modified alkyd resins of the invention that are present in theaqueous paints of the invention have self-crosslinking properties. Thesame applies accordingly to the adhesives and sealing compounds of theinvention.

Where the coating materials, adhesives, and sealing compounds of theinvention are to be curable not only thermally but also with actinicradiation (dual cure), they comprise customary and known additives whichcan be activated with actinic radiation. In the context of the presentinvention, actinic radiation means electromagnetic radiation, especiallyvisible light, UV light or x-rays, or corpuscular radiation, especiallyelectron beams. Particular preference is given to employing UV light.Examples of suitable constituents which can be activated with actinicradiation are (meth)acryloyl-, allyl-, vinyl- ordicyclopentadienyl-functional (meth)acrylate copolymers or polyetheracrylates, polyester acrylates, unsaturated polyester acrylates, epoxyacrylates, urethane acrylates, amino acrylates, melamine acrylates,silicone acrylates or the corresponding methacrylates.

The aqueous paint of the invention may further comprise customary andknown binders, especially hydroxylcontaining binders, as additives.

The binders may originate from any of a wide variety of classes ofoligomer and polymer. Examples of suitable oligomer and polymer classesare random, alternating and/or block, linear and/or branched and/orcomb, addition (co)polymers of olefinically unsaturated monomers, orpolyaddition resins and/or polycondensation resins. For further detailsof these terms refer to Römpp Lexikon Lacke und Druckfarben, GeorgThieme Verlag, Stuttgart, New York, 1998, page 457, “Polyaddition” and“Polyaddition resins (Polyadducts)”, and also pages 463 and 464,“Polycondensates”, “Polycondensation”, and “Polycondensation resins”. Asregards substituents or reactive functional groups that may be present,the comments made above with regard to the monomers (a) applyanalogously.

Examples of highly suitable addition (co)polymers arepoly(meth)acrylates and partially hydrolyzed polyvinyl esters.

Examples of highly suitable polyaddition resins and/or polycondensationresins are polyesters, alkyd resins, including those described herein,polyurethanes, polylactones, polycarbonates, polyethers, epoxyresinamine adducts, polyureas, polyamides or polyimides.

Further examples of suitable additives are organic and inorganicfillers, thermally curable reactive diluents, siccatives, low-boilingand/or high-boiling organic solvents (“long solvents”), UV absorbers,light stabilizers, free-radical scavengers, thermolabile free-radicalinitiators, crosslinking catalysts, devolatilizers, slip additives,polymerization inhibitors, defoamers, emulsifiers, wetting agents,adhesion promoters, leveling agents, film forming auxiliaries, rheologycontrol additives or flame retardants. Further examples of suitablecoatings additives are described in the text book “Lackadditive” byJohan Bieleman, Wiley-VCH, Weinheim, New York, 1998.

As mentioned above, in the context of the process of the invention thesecustomary coatings additives may already be added to the dispersions 1,provided they do not inhibit or suppress entirely the graftcopolymerization.

The preparation of the aqueous coating materials of the invention,especially the aqueous paints, adhesives, and sealing compounds, has nospecial features but instead takes place in a customary and known mannerby mixing of the above-described constituents in suitable mixingequipment such as stirred tanks, dissolvers, stirrer mills or extruders,in accordance with the techniques that are suitable for the preparationof the respective coating materials, adhesives, and sealing compounds.

The adhesives of the invention serve for producing adhesive films of theinvention on primed and unprimed substrates.

The sealing compounds of the invention serve for producing seals of theinvention on and in primed and unprimed substrates.

The aqueous coating materials of the invention serve for producingsingle-coat or multicoat clearcoat systems or color and/or effect paintsystems on primed and unprimed substrates.

Very particular advantages result in the context of their use forproducing pigmented basecoats, especially as part of what is known asthe wet-on-wet technique, in which a basecoat material, especially anaqueous basecoat material, is applied to the primed or unprimedsubstrate and dried but not cured and then a clearcoat material isapplied to the basecoat film and the resulting clearcoat film is curedtogether with the basecoat film, thermally or both thermally and withactinic radiation (dual cure).

Suitable substrates include all surfaces to be coated that are notdamaged by curing of the films present thereon using heat or using heatand actinic radiation in combination (dual cure); they include, forexample, metals, plastics, wood, ceramic, stone, textile, fibercomposites, leather, glass, glass fibers, glass wool, rock wool,mineral-bound building materials and resin-bound building materials,such as plasterboard panels, cement slabs or roofing shingles, andcomposites of these materials. Accordingly, the coatings, adhesive filmsor seals of the invention are also suitable for applications outside ofautomotive OEM finishing and automotive refinish. In these contexts theyare suitable particularly for the coating, adhesive bonding and/orsealing of furniture and for industrial application, including coilcoating, container coating, and the impregnation or coating ofelectrical components. In the context of the industrial applicationsthey are suitable for coating, bonding and/or sealing virtually allparts for private or industrial use such as radiators, domesticappliances, small metal parts such as nuts and bolts, hubcaps, wheelrims, packaging or electrical components such as motor windings ortransformer windings.

In the case of electrically conductive substrates it is possible to useprimers, which are produced in conventional manner from electrocoatmaterials. Both anodic and cathodic electrocoat materials may be usedfor this purpose, but especially cathodics.

It is also possible to coat, bond or seal primed or unprimed plasticsparts made, for example, from ABS, AMMA, ASA, CA, CAB, EP, UF, CF, MF,MPF, PF, PAN, PA, PE, HDPE, LDPE, LLDPE, UHMWPE, PC, PC/PBT, PC/PA, PET,PMMA, PP, PS, SB, PUR, PVC, RF, SAN, PBT, PPE, POM, PUR-RIM, SMC, BMC,PP-EPDM and UP (abbreviations to DIN 7728 T1). Unfunctionalized and/orapolar substrate surfaces may be subjected prior to coating in a knownmanner to a pretreatment, such as with a plasma or by flaming, or may beprovided with a hydroprimer.

The application of the adhesives, sealing compounds, and coatingmaterials of the invention may take place by any customary applicationmethod, such as spraying, knifecoating, spreading, flowcoating, dipping,impregnating, trickling or rolling, for example. The substrate to becoated may itself be at rest, with the application equipment or unitbeing moved. Alternatively, the substrate to be coated, especially acoil, may be moved, with the application unit being at rest relative tothe substrate or being moved appropriately. Where the adhesives, sealingcompounds, and coating materials of the invention include constituentswhich can be activated with actinic radiation, application is preferablyconducted in the absence of light.

Depending on their physical composition, the applied films of theadhesives, sealing compounds, and coating materials of the invention maybe cured oxidatively, (air drying), thermally, or both thermally andwith actinic radiation.

In the case of oxidative curing, no further measures in terms ofapparatus need be taken. If desired, oxidative curing may be assisted bymeans of higher temperatures.

Following, where appropriate, a certain rest period, which serves forthe leveling of the films and/or for the evaporation of volatileconstituents, the applied films of the adhesives, sealing compounds, andcoating materials of the invention may also be subjected conventionallyto thermal curing or to curing thermally and with actinic radiation.

In terms of method the thermal cure has no special features; instead,the customary and known temperatures in the range from room temperatureto 200° C., curing times in the range from one minute to three hours,and apparatus such as radiant heaters or forced air ovens are employed.

The actinic radiation cure also has no special features in terms of itsmethod but instead takes place in conventional manner by irradiationwith UV lamps and/or electron beam sources, preferably under inert gas.

In the case of the curing of the dual-cured adhesives, sealingcompounds, and coating materials of the invention, thermal curing andactinic radiation curing may be used simultaneously or alternately.Where the two curing methods are used alternately, it is possible, forexample, to begin with the thermal cure and end with the actinicradiation cure. In other cases it may prove advantageous to begin and toend with the actinic radiation cure. The skilled worker is able todetermine the curing method most advantageous for the case in hand onthe basis of his or her general art knowledge with the assistance, whereappropriate, of simple preliminary tests.

The adhesive films and seals of the invention that are produced from thesealing compounds of the invention have outstanding adhesion andsealability even under extreme climatic conditions and even over longperiods of time.

The coatings of the invention that are produced from the coatingmaterials of the invention exhibit excellent leveling and have anoutstanding overall appearance. They are stable to weathering, resistantto acid and moisture, and do not yellow even under tropical conditions.They can therefore be used in the interior sector and in the exteriorsector.

Accordingly, the primed and unprimed substrates of the invention,especially bodies of automobiles and commercial vehicles, industrialcomponents, including plastics parts, packaging, coils, and electricalcomponents, or furniture that have been coated with at least one coatingof the invention, sealed with at least one seal of the invention and/orbonded using at least one adhesive of the invention, are notable forparticular technical and economic advantages, in particular a longservice life, which makes them particularly attractive to users.

EXAMPLES Preparation Example 1 The Preparation of an Alkyd ResinContaining Allyloxy Groups, for Inventive Use

225 parts by weight of coconut fatty acid, 30.5 parts by weight ofbenzoic acid, 368.5 parts by weight of trimethylolpropane, 63.6 parts byweight of diethylene glycol, 207.5 parts by weight of isophthalic acid,0.2 parts by weight of tin oxide hydrate, 185 parts by weight ofphthalic anhydride, 62.64 parts by weight of trimethylolpropanemonoallyl ether and 60 parts by weight of xylenes were weighed out intoa stirred tank which is suitable for preparing alkyd resins and isequipped with reflux condenser, water separator and stirrer.Subsequently, the temperature of the mixture was raised to a maximum of230° C. until an acid number of less than 10 mg KOH/g had been reached.It was subsequently cooled to 160° C. and 96.0 parts by weight oftrimellitic anhydride were added to the reaction mixture. Thetemperature of the reaction mixture was raised to 180° C. until an acidnumber of from 30 to 35 mg KOH/g had been reached and the viscosity ofthe reaction mixture (60% in propylene glycol) was from 5.0 to 6.0 dpas.The solids content was 100% by weight. The glass transition temperatureof the alkyd resin was −23° C. Its number-average molecular weight was1762 Dalton; the polydispersity of the molecular weight, Mw/Mn, was 3.0.The alkyd resin was diluted with propylene glycol to give a solidscontent of 85% by weight.

Example 1 The Preparation of a Dispersion of the Invention

938 parts by weight of water and 300 parts by weight of the 85% alkydresin of Preparation Example 1 were weighed out into a reaction vesselsuitable for polymerization and equipped with stirrer, reflux condenserand two feed vessels, and this initial charge was heated to 80° C. 36.2parts by weight of dimethylethanolamine were added to the resultingmixture with stirring. After this, the dispersion had a solids contentof 20% by weight. Metered into this dispersion at a reaction temperatureof 82° C., beginning simultaneously, were on the one hand a mixture of64.5 parts by weight of styrene, 75.2 parts by weight of hydroxyethylmethacrylate, 56.8 butyl methacrylate and 31.4 parts by weight ofmethacrylic acid, metered in over the course of two hours, and on theother hand a mixture of 11.5 tert-butyl peroxy-2-ethylhexanoate and 6parts by weight of propylene glycol, metered in over the course of 2.25hours. After the end of the feeds, the resultant dispersion waspostpolymerized at 82° C. for four hours. Then, at a reactiontemperature of 82° C., beginning simultaneously, on the one hand amixture of 114 parts by weight of styrene, 127 parts by weight ofhydroxyethyl methacrylate and 27.5 parts by weight of butyl methacrylatewas metered in over the course of three hours and on the other hand amixture of 19 parts by weight of tert-butyl peroxy-2-ethylhexanoate and12 parts by weight of propyl glycol was metered in over the course of3.25 hours. After the end of the feeds, the resulting dispersion waspostpolymerized at 82° C. for four hours. The result was a dispersion ofthe invention having a solids content of 64% by weight. The acid numberof the acrylate-modified alkyd resin was 33.5 mg KOH/g. Its hydroxylnumber (theoretical) was 123 mg KOH/g. the dispersion was neutralized to80 mol % with dimethylethanolamine. After this, the dispersion had a pHof 7.3. It could be stored at 40° C. for eight weeks without anyformation of a sediment.

For use for preparing aqueous paints of the invention, the dispersionwas adjusted with water to a solids content of 40% by weight. Thedispersion of the invention was outstandingly suitable for thepreparation of two-component systems and one-component systems,especially two-component paints and one-component paints.

Preparation Example 2 The Preparation of an Alkyd Resin ContainingAllyloxy Groups, for Use in Accordance with the Invention

193.8 parts by weight of Juvandole fatty acid, 193.8 parts by weight ofsunflower fatty acid, 16.9 parts by weight of benzoic acid, 204.1 partsby weight of trimethylolpropane, 14.1 parts by weight of diethyleneglycol, 114.9 parts by weight of isophthalic acid, 0.11 parts by weightof tin oxide hydrate, 106.6 parts by weight of hexahydrophthalic acid,69.4 parts by weight of trimethylolpropane monoallyl ether and 33.2parts by weight of xylene were weighed out into a stirred tank suitablefor preparing alkyd resins and equipped with reflux condenser, waterseparator and stirrer. The temperature of the mixture was then raised tonot more than 230° C. until an acid number of less than 10 mg KOH/g hadbeen reached. It was then cooled to 160° C. and 53.2 parts by weight oftrimellitic anhydride were added to the reaction mixture. Thetemperature of the reaction mixture was raised to 180° C. until an acidnumber of from 30 to 35 mg KOH/g had been reached and the viscosity ofthe reaction mixture (60% in propylene glycol) was from 1.0 to 2.0 dPas.The solids content was 100% by weight.

Example 3 The Preparation of a Dispersion of the Invention

410.8 parts by weight of water, 13.8 parts by weight of a commercialemulsifier (Pluriol® A 010 R), 23.1 parts by weight of butyl glycol and130.9 parts by weight of the alkyd resin according to PreparationExample 2 were weighed out into a reaction vessel suitable forpolymerization and equipped with stirrer, reflux condenser and two feedvessels, and this initial charge was heated to 80° C. 19.3 parts byweight of dimethylethanolamine were added to the resulting mixture withstirring. After this, the dispersion had a solids content of 25% byweight. Metered into this dispersion at a reaction temperature of 82°C., beginning simultaneously, were on the one hand a mixture of 58.5parts by weight of styrene, 44.2 parts by weight of hydroxyethylmethacrylate, 70.1 parts by weight of butyl acrylate and 16.1 parts byweight of methacrylic acid, metered in over the course of three hours,and on the other hand a mixture of 9.83 parts by weight of tert-butylperoxy-2-ethylhexanoate and 6.1 parts by weight of butylene glycol,metered in over the course of 3.25 hours. After the end of the feeds,the resultant dispersion was postpolymerized at 82° C. for four hours.Then, at a reaction temperature of 82° C., beginning simultaneously, onthe one hand a mixture of 33.1 parts by weight of styrene, 22.6 parts byweight of hydroxypropyl acrylate and 54.2 parts by weight of butylacrylate was metered in over the course of two hours and on the otherhand a mixture of 5.9 parts by weight of tert-butylperoxy-2-ethylhexanoate and 3.1 parts by weight of propylene glycol wasmetered in over the course of 2.25 hours. After the end of the feeds,the resulting dispersion was postpolymerized at 82° C. for four hours.Thereafter, sufficient water was added to give a dispersion of theinvention having a solids content of 48% by weight. The dispersion pHwas 7.3. The acrylate-modified alkyd resin of the invention had an acidnumber of 33.5 mg KOH/g, a theoretical hydroxyl number of 84 mg KOH/gand a glass transition temperature of 6.5° C.

The dispersion of the invention could be stored at 40° C. for eightweeks without any formation of a sediment. For use for preparing aqueouspaints of the invention, it was adjusted with water to a solids contentof 40% by weight.

Example 4 Preparation of an Aqueous Oxidatively Drying Paint of theInvention

To prepare the aqueous oxidatively dry paint of the invention, first ofall a white pigment paste was prepared from 18 parts by weight of thedispersion from Example 3, 3 parts by weight of deionized water, 8.9parts by weight of a commercial dispersing assistant (Disperse Ayd® W22Rfrom Krahn Chemie) and 60 parts by weight of titanium dioxide (rutiletype R-HD2 R from Thioxide). The constituents were mixed and theresulting mixture was adjusted with water to a solids content of 70% byweight and ground on a bead mill until a pigment particle diameter of<15 μm had been reached.

Metered in to 64 parts by weight of the dispersion from Example 3 were1.8 parts by weight of a siccative mixture consisting of strontiumoctoate, cobalt octoate and calcium octoate (50% by weight solidscontent; Siccatol® R938 from Akzo). Then 21 parts by weight of theabove-described white pigment paste, 4 parts by weight of butyleneglycol, 0.5 parts by weight of a commercial thickener (Rheolate® R278from Kronos Titan) and 0.4 parts by weight of a commercial defoamer(Byk® R024 from Byk Chemie) were added. Subsequently, 5.0 parts byweight of a commercial wax emulsion (Aquacer® R535 from Byk-Cera Chemie)and 0.3 parts by weight of a Theological assistant (Bentone® R L/T fromKronos Titan) were incorporated. The resultant aqueous paint of theinvention was adjusted with water to application viscosity.

The aqueous paint of the invention could be applied to a wide variety ofsubstrates, such as wood, glass, plastics or steel. Following oxidativedrying, it gave coatings exhibiting very good leveling, high gloss andhigh hiding power.

What is claimed is:
 1. An aqueous dispersion of an acrylate-modified alkyd resin that is prepared in the presence of at least one water-miscible diol by a process comprising (1) dispersing in water at least one alkyd resin containing, based on its total amount, from 0.1 to 10% by weight of allyloxy groups, wherein the allyoxy groups are at least one of pendant and terminal, to give a dispersion 1, (2) graft copolymerizing a mixture of methacrylic acid and at least one further, carboxyl-free olefinically unsaturated monomer in dispersion 1 to give a dispersion 2, and (3) graft copolymerizing once or n times at least one of: (3.1) at least one olefinically unsaturated monomer that is free from acid groups, and (3.2) at least one mixture of at least one olefinically unsaturated monomer that contains acid groups and at least one olefinically unsaturated monomer that is free from acid groups, in dispersion 2 or dispersion 2 to n−1 resulting from the respective preceding step (2) or (2) to (n−1) of the process, with the proviso that in step (3) of the process or its repetitions (3) to (n), acid groups are incorporated in an amount that corresponds in total to not more than 90 mol % of the amount of acid groups incorporated in step (2) of the process.
 2. The aqueous dispersion of claim 1, wherein the alkyd resin, based on its total amount, contains from 0.1 to 10% by weight of allyl ether groups.
 3. The aqueous dispersion of claim 1, wherein the alkyd resin has an oil content, based on its total amount, of from 20 to 70% by weight.
 4. The aqueous dispersion of claim 1, wherein the acrylate-modified alkyd resin, based on the resin, contains from 20 to 80% by weight of graft-copolymerized polyacrylate.
 5. The aqueous dispersion of claim 1, wherein the graft copolymerization is conducted in the presence of at least one of ethylene glycol, propylene glycol, and butylene glycol.
 6. The aqueous dispersion of claim 1, wherein the graft copolymerization is conducted in the presence of at east one coatings additive.
 7. A composition comprising at least one aqueous dispersion of claim 1, wherein the composition is one of an air-drying coating material, an adhesive, and a sealing compound.
 8. The composition of claim 7, wherein the composition is thermally curable.
 9. The composition of claim 8, wherein the composition further comprises at least one crosslinking agent.
 10. A substrate comprising of a coating, an adhesive film, and a sealed from the composition of claim
 7. 11. A substrate comprising one of a coating, an adhesive film, and a seal formed from the composition of claim
 9. 